Gyroscopic control mechanism



Feb. 6, 1962 E. H. GAHN 3,019,662

GYROSCOPIC CONTROL MECHANISM Filed April 14, 1955 3,619,662 GYRQSCOPEC(IONTROL MECHANISM Edwin H. Gahn, Normandy, Mo., assignor, by mesneassignments, to Systron-Donner Corporation, Concord, Califi, acorporation of California Filed Apr. 14, 1955, Ser. No. 501,240 12Claims. (Cl. 745.7)

The present invention relates generally to gyroscopic controls, and moreparticularly to a novel self-powered gyroscopic control mechanism ofunusually small size and exceptionally high sensitivity.

Although the principle of the gyroscopic control has long been known,the increasing demand for automatically controlled, self-propelled unitshas brought forth a great deal of effort directed to improvements inboththe directional accuracy and the sensitivity of response in gyroscopicunits adapted for directional control. As an example, a gyroscopicintelligence unit for directional control of a guided missile must havethe attributes of accuracy and sensitivity above mentioned in thehighest degree, and must at the same time be truly miniature in bothsize and weight. Additionally, the rotating assembly must have thelowest power requirement consistent with the necessary speed of rotationto provide the desired accuracy of response, and the torque requirementsto maintain a constant rotor speed should not vary appreciably uponoperative disturbance from the principal axis of the unit.

It is an object of the present invention, therefore, to provide a novelself-powered gyroscopic control mechanism which avoids the use of gimbalframes for support of the rotating element.

It is another object of the invention to provide a novel gyroscopiccontrol mechanism which incorporates a squirrel cage rotor disposedexternally of a fixed stator, the rotor being at all times concentricwith the spin axis of the gyroscopic mechanism.

It is another object of the invention to provide a novel gyroscopiccontrol mechanism incorporating an induction motor in which the statortakes the general form of a symmetrical segment of a sphere, and inwhich the rotor is formed so as to be complementary therewith.

It is another object of the invention to provide a novel gyroscopiccontrol mechanism in which the rotor has universal pivotal movementrelative to the stator without consequent deterioration of the drivingtorque.

The foregoing, along with additional obiects and advantages, Will beapparent from the following description taken in conjunction withtheaccompanying drawing, in which:

FIGURE 1 is a side elevational view of a gyroscopic control mechanismconforming to the present invention, certain cooperative structure beingillustrated in broken outline;

' FIGURE 2 is a vertical sectional view taken generally on thelongitudinal axis of the mechanism;

FIGURE 3 is a vertical sectional view taken generally along the line 3-3in FIGURE 1;

IGURE 4- is a vertical sectional view taken generally along the line 4-4in FIGURE 1;

FIGURE 5 is a vertical sectional view taken generally along the line 5-5in FIGURE 1 and drawn to reduced scale; and

FIGURE 6 is a side elevation of a removed support.

Referring to the drawing more particularly through the use of referencecharacters, the numeral 10 desigatcnt intense Patented Feb. 6, 19%32nates generally a gyroscopic control mechanism constructed in accordancewith the teachings of the present invention. This mechanism 10 comprisesa fixed stator assembly 12, a movable rotor assembly 14, and a shiftablecaging assembly 16.

Directing attention first to the stator assembly 12, a support 18 havinga sleeve-like barrel 20 provided with a radial mounting flange 22hasmounted therein a double-row ball bearing assembly 24. This ball hearingassembly 24 is of the self-aligning type, and its outer race ismaintained in fixed position relative to the barrel 20 by means of anannular retainer 26 threadedly received in the barrel 20 as clearlyillustrated in FIGURE 2. A stack of laminations 28, provided withconventional slots 30 for receiving windings 32, is mounted on theoutside of the barrel 20, being positioned by means of aflange 34integral with the support 18 so that the longitudinal center of thelaminated stack 28 is in alignment with the longitudinal center of thebearing assembly 24. The stack 28 and the support 18 are securedtogether by well-known means, such as cycle welding, for example. Theperiphery of the laminated stack 23 is formed, preferably with a highdegree of accuracy, to a spherical surface, the spherical center beingat the pivotal center of the self-aligning bearing assembly 24.

The assembled stator assembly 12 is, as illustrated in the drawing,adapted to be mounted against a wall or bulkhead 36 by means of screws38 which threadedly engage the mounting flange 22.

Turning attention now to the rotor assembly 14, an elongated shaft 40 ismounted near one of its ends within the inner race of the self-aligningbearing assembly 24, this mounted relationship being maintained by ashaft nut 42 engaging the extreme end of the shaft 40. The nut 42 isprovided with an end recess 44 disposed axially beyond the adjacent endof the shaft 44 as clearly illustrated in FIGURE 2. It may be noted atthis time that the recess 44 accommodates the free end of a rod-likedirection stop 46 mounted in the bulkhead 36 and secured by a setscrew48. The significance of this arrangement will be explained more fullyhereinafter.

With one of its ends mounted as above described, the shaft 4% extendsthrough the annular retainer 26 and beyond the end of the support 18,where it mounts a Wheel St). The Wheel 50 has a hub portion 52 whichfits a slightly enlarged portion 54 of the shaft 4ft, a radial disc-likeportion 56 which is secured by means of screws 58 to a radial flange eaformed integral with the shaft 4t), and a rim portion 62 which isaxially extended so as to encompass substantially the whole of thestator assembly 12.

The inside of the rim portion 62 of the wheel 54 is formed to receivetwin squirrel cages 64, each comprising a stack of laminations 66flanked by end rings 68 electrically interconnected by conducting bars70 in the usual manner. The annular squirrel cages 64 are disposed inside-by-side abutment and have their inward surfaces formed to aspherical shape so as to be complementary with the external sphericalsurface presented by the laminated stack 28 aforementioned. The squirrelcages 64 are positioned axially Within the wheel 5% by means ofsetscrews 72 and are then secured in place by well known means, such ascycle welding. The open end of the wheel 50 comprising that part of therim portion 62 which extends beyond the squirrel cages 64 is internallythreaded so as to receive a balance ring 74 which may be adjustedaxially to achieve a desired balance of the complete rotor assembly 14.

The relationship between the squirrel cages 64 and the laminated stack28' is clearly such that the former can rotate freely around thelongitudinal axis of the bearing assembly 24 and can also swivel orpivot in all directions about the pivot center of the bearing 24. Thereis, of course, the usual uniform air gap between the stator laminations28 and the squirrel cage laminations 66, and the illustrated greaterthickness of the laminated stack 28 as compared with the twin squirrelcages 64 insures that the magnetic fiux between these parts remainssubstantially constant regardless of changes in relative positionstherebetween. The direction stop 46 limits the swiveling movement of therotor assembly to a permissible maximum.

Returning to the shaft 40 an integral extension 76 extends beyond theflange 60 and is provided with a disclike flange 73 for transmittingcertain intelligence derived from operation of the mechanism 10, as willbe more fully explained hereinafter. Finally, the shaft 46 terminates ina knob-like journal portion 80 having a tapered end 82. As bestillustrated in FIGURE 1, the journal portion *80 is adapted to fitwithin a ball cage 84 forming part of a ball bearing 86. The cagingassembly 16, however, is movably mounted in a bulkhead shown in brokenlines as 88, and it will be understood that under certain circumstances,the bearing 86 may be withdrawn from the position of FIGURE 1 to thatillustrated in FlGURE 2, so as to be completely disengaged from theshaft 40.

Operation As previously noted, the gyroscopic control mechanism of thepresent invention is particularly adapted for use in applications wheresmall size is mandatory, without sacrifice in either sensitivity ofresponse or accuracy of transmitted intelligence. A typical applicationwould be in the control of automatically guided missiles.

In such an application, the mechanism is installed within a casing, suchas 90, shown in broken lines in FIGURES 1 and 2, provided with bulkheadassemblies 36 and 88 for mounting the parts as illustrated. Initialoperation of the mechanism 1.0 is with the caging assembly 16 in theposition of FIGURE 1, the windings 32 of the stator assembly 12 beingenergized from an appropriate source of electricity (not shown) carriedwithin the missile. The spin axis of the caged shaft 40' is, of course,disposed at least parallel with, and preferably concentric with, thelongitudinal axis of the missile, illustrated in the present example bythe casing 90.

Preferably, the rotor assembly 14 is permitted to attain a stabilizedrotational velocity before the missile is launched, and the shaft 40 isretained in caged condition until after the initial acceleration of thelaunching operation. After the missile has been launched, however, thecaging assembly 16 is automatically withdrawn so that the shaft 41) isfree to pivot about the pivotal center of the self-aligning ball bearingassembly 24, or more accurately, the missile itself is enabled to gyraterelative to the gyroscopically maintained axial alignment of the rotorshaft 40.

It is obvious, of course, that any deviation of the missile from itspreestablished straight course will be reflected in relativedisplacement of the axis of the missile relative to the axis of therotor shaft 4i). Thus, it becomes necessary only to detect the directionof displacement in order to provide appropriate counteractingprocedures. A system of pick-off devices (not shown) arrangedcircumferentially around the periphery of the disc-like flange 78 inposition to be influenced by very slight relative movements of thelatter will detect the desired intelligence.

Clearly, there has been described a gyroscopic control mechanism whichfulfills the objects and advantages sought therefor.

It is to be understood that the foregoing description and theaccompanying drawing have been given only by way of illustration andexample. It is further to be un derstood that changes in the form of theelements, rearrangement of parts, or the substitution of equivalentelements, all of which will be apparent to those skilled in the art, arecontemplated as being within the scope of the invention, which islimited only by the claims which follow.

What is claimed is:

l. A gyroscope control mechanism comprising, in combination,electromagnetic prime mover means including a first stator assembly andmovable rotor assembly, and a self-aligning ball bearing assembly havinga central pivot point in fixed relation to said stator assembly, saidrotor assembly being rotatably retained and supported by said bearingassembly for universal pivotal movement about said central pivot point,the stator assembly including a stack of laminations in encirclingrelation to the ball bearing assembly, and electrical conducting meansassociated therewith for establishing a magnetic field, the rotorassembly including squirrel cage inducting means in encircling relationto the stator laminations.

2. The mechanism of claim 1 wherein the stack of stator laminations isformed to a convex spherical surface and the squirrel cage means in therotor is provided with a concave spherical surface, the centers of saidconvex and concave spherical surfaces being substantially coincidentwith the central pivot point defined by the aforesaid ball bearingassembly.

3. A gyroscopic control mechanism, comprising, in combination, aSUPPOIT, an electromagnetic stator assembly alfixed to the support, africtionless self-aligning ball bearing assembly mounted in the supportand defining a pivotal center therein, and wheel means including asquirrel cage rotor assembly supported in said bearing assembly for bothcontinuous rotation and limited universal pivotal movement about asubstantially horizontal axis.

4. The mechanism of claim 3 wherein said stator assembly, said rotorassembly, and said bearing assembly have coincident center points ofsymmetry.

5. A gyroscopic control mechanism comprising, in combination, a tubularsupport, an annular electromagnetic stator assembly disposed externallyof said support, a swivel bearing disposed internally of said support,and an elongated rotor shaft having sole support adjacent one end insaid bearing for unrestrained combined rotation and swiveling movement,said shaft extending longitudinally beyond said tubular support, abowl-shaped wheel having a hub portion secured to said shaft beyond saidsupport and a rim portion which encompasses said stator assembly, and anannular induction assembly affixed within said rim portion for primemoving cooperation with said electromagnetic stator assembly.

6. The mechanism of claim 5 with the addition of a balancing ringadjustably disposed in the free end of said rim portion for acheving adesired condition of balance in the rotating assembly.

7. The mechanism of claim 6 wherein the induction assembly and thestator assembly are concentric, one being provided with a convexspherical surface and the other being provided with a concave sphericalsurface.

8. The mechanism of claim 7 wherein the stator assembly is of greateraxial length than the induction assembly.

9. The mechanism of claim 5 wherein the end of the shaft remote from theaforementioned bearing is formed for removable supported engagement in acaging assembly.

10. The mechanism of claim 5 wherein the shaft is provided with acircular radial flange remote from the bearing supported end.

1-1. In a gyroscopic control mechanism, a rotor assembly comprising anelongated shaft, means adjacent one end of said shaft for mounting it inthe movable race of a self-aligning frictionless bearing, means at theopposite end of said shaft for restrained engagement with a cagingdevice, means on the shaft adjacent said opposite end thereof forinfluencing a pick-01f device, a wheel including a hub portion afiixedto a central portion of said shaft, said wheel further including anaxially extended rim portion encircling the electromagnetic inductionmeans including a laminated assembly formed to a concave spherical shapesymmetrically related to the pivot center of that portion of said shaftto be disposed in said movable race aforementioned, and means adjustablymounted at the free end of said rim portion for balancing the rotorassembly about said pivot center.

12. In a gyroscopic control mechanism, a hollow cantilever support, aself-aligning substantially frictionless bearing mounted within saidhollow support, an electromagnetic stator assembly mounted on saidsupport, said stator assembly including a core structure formed to asymmetric convex spherical shape concentric with the pivot center ofsaid bearing, and an electromagnetic rotor assembly mounted in saidbearing for both rotational and pivotal movement about said pivotcenter, said rotor assembly including a core structure formed to asymmetrical concave spherical shape concentric With said pivot center.

References Cited in the file of this patent UNITED STATES PATENTS791,983 Leblanc June 6, 1905 1,495,769 Brewerton May 27, 1924 1,802,108Chessin Apr, 21, 1931 1,959,309 Smith May 15, 1934 1,984,874 GillmorDec. 18, 1934 2,093,503 Wittkuhns Sept. 21, 1937 2,138,531 Wise et al.Nov. 29, 1938 2,384,761 Mehan Sept. 11, 1945 2,423,270 Summers July 1,1947 2,452,335 Stoner Oct. 26, 1948 2,581,965 Miller Jan. 8, 19522,708,369 Dixson May 17, 1955 FOREIGN PATENTS 1,082,038 France June 16,1954 150,452 Great Britain Sept. 9, 1920 554,594 Great Britain July 12,1943

